In the Garden:Coastal and Tropical South
April, 2010
Regional Report

Starting its tiny seeds may be a challenge, but once planted, flowering tobacco takes care of itself.

Perennial Pleasures

Everybody likes a plant that looks nice at least most of the year and blooms regardless of what we do or don't do for it. Some such plants are plastic or silk, but others are perennial favorites in our regions.

Different Perennial Definitions
The plants that are perennial in both our zones are seldom grouped together, but should be. Although our zones are USDA 8b-10, a decidedly diverse range, our idea of a perennial plant is different. The old joke is that a perennial is a plant that, had it survived, would have bloomed for years. In reality, a perennial is any plant that can be expected to live for 3 or more years. These are primarily green-stemmed, not woody plants and, in our regions, may or may not die down in winter. We grow perennials in beds and borders, like everyone else, but we also put them in pots. Particularly those that only brown in truly severe conditions, like soap aloe, make fine patio plants alone or in big combination pots usually reserved for annuals.

The Lantana Example
The many popular varieties and forms of lantana can brown to the ground in a severe winter on the Gulf Coast, but may never lose itheir green in Miami. Either way, this summer bloomer benefits from late winter pruning to rejuvenate its flowering stems. That timing would be ill-advised in other regions, but a difference in pruning practices is another hallmark of "our" perennials. Common garden wisdom says to prune perennials in the season opposite their bloom and that does work. However, we tend to also follow the growth pattern of the plant, which is another way of saying that we cut back as needed. Often that is in late winter for perennials that bloom in summer, and summer or fall for the spring flowers like LA iris. We may also prune during the growing season to renew flowering stems and control height, but also to reduce insect populations such as spider mites on the aforementioned lantana. Such cutting back has the added benefit of sparking an entirely new set of leaves, as well as flowers, and gives you time to address the mite issue. In dry beds, spider mites form nests under leaves, safe from their nemesis, water. If you string a sprinkler hose under such plants or remember to spray under their leaves occasionally, the mites will move on.

Overlooked Perennials for our Zones
The list could be quite long, but here's a sampling of my favorites:
Egret flower (Habenaria radiata) is well-named, for its flowers do look like tiny birds. Held almost flat atop dark green leaves, their fringed edges are stunning. Grow these egrets from tiny peanut-looking bulbs in water gardens or, like the better known white spider lily, in beds or pots with regular watering.

Our regions prize tropical hibiscus, but the perennial types (H. moscheutos hybr.) have fewer pests and are not attractive to deer. Besides, there's no easier 4' hedge to grow at the back of a border and none other with flowers the size of dinner plates.

Perennial cosmos are taken for granted, but the fragrant "Chocolate" (Cosmos atrosanguineus) got my attention. Combined with common yellow cosmos, calliopsis and Mexican hat (Ratibida), this planting produced waves of bold color in a dry section of garden. In Greek, "cosmos" means "balanced universe" and that swath of flowers certainly lived up to its name.

Another fine combo for dry areas is gallardia and fernleaf yarrow. Both were popular for years, then seen as too common. Now they've been reintroduced, along with improved selections. Or try soap aloe backed up by 'Black Magic' elephant ear. It looks amazing and the aloe's flower spikes of trumpet-shaped blossoms nurture hummingbirds.